Here is a really good video explaining DIT

You can skip to 9:35

 

Just watched the whole video. Unfortunately this is the results we as customers have to deal with due to the new environmental regulations. We cant necessarily blame Subaru for it. Although dual injection would be a nice touch, just wonder how it all works with a "flat" engine vs an I or V. Thank you for the info.

I don't think the engine layout would make any major difference here. But an oil catch can could at least prolong the time between the need to take action on carbon build-up.

 

 

I'd expect that in the future we would see some way or another to inject fluid in the manifold that can dissolve the carbon build-up, similar to the DEF for diesels in the exhaust of diesels.

At 7:25, the presenter completely blows the source of crankcase pressure. The cylinder pressure leak past the piston rings into the crank case where the piston and rods are not the other way around. It is kind of hard for me to take this video tech seriously with such a major misunderstanding of crankcase pressure.

I don't think the engine layout would make any major difference here. But an oil catch can could at least prolong the time between the need to take action on carbon build-up.

 

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I think that is optimistic, possibly depending on engine design. VW owners that have installed catch cans have reported minor reductions in carbon buildup, but it apparently does nothing to help BMW owners.

 

There needs to be active measures to clean the intake valves.

Well, I never stated how much it would prolong the time!

 

 

And some carbon build-up comes from back-blow from the cylinder, which don't help.

And some carbon build-up comes from back-blow from the cylinder ...

... and some results from oil migration down the intake valve guides.

Good info.

This is the reason I've decided to skip the 2020 DIT. After a couple of years we'll know how the engine does with this problem but until then I want no part of it.

I don't think the engine layout would make any major difference here. But an oil catch can could at least prolong the time between the need to take action on carbon build-up.

 

 

I'd expect that in the future we would see some way or another to inject fluid in the manifold that can dissolve the carbon build-up, similar to the DEF for diesels in the exhaust of diesels.

 

You mean like methanol injection?

Just use a catch can and run a can of seafoam through the intake during your air filter scheduled maintenance. Then change the oil after seafoaming. Say every 30k miles, and you'll probably tire of the car before it fails due to carbon build up.

I read methanol will keep it from building it up, but doesn't significantly remove it. A treatment of Seafoam will not remove a significant amount either.